#define _CRT_SECURE_NO_WARNINGS
#define N 50
#include<stdio.h>
#include<assert.h>
#include<string.h>
char* My_strcat(char* arr1, char* arr2)
{
	char* ret = arr1;
	while (*arr1)
	{
		++arr1;
	}
	while (*arr1++ = *arr2++)
	{
		;
	}
	return ret;
}
int main()
{
	char arr1[50] = "hello";
	char arr2[] = " world";
	My_strcat(arr1, arr2);
	printf("%s", arr1);
	return 0;
}